HARTFORD, Conn. (AP) — Members of a state commission reviewing the Newtown school massacre say they still need more information and documentation about the shooter and his mental health history, despite the recent release by police of thousands of pages of investigative documents.

Hamden Mayor Scott Jackson, chairman of the Sandy Hook Advisory Commission appointed by Gov. Dannel Malloy, said the panel still doesn’t have enough information to make substantial recommendations on changes to the mental health system in the wake of the Dec. 14, 2012, shooting, which left 20 first-graders and six educators dead at Sandy Hook Elementary School. The shooter, 20-year-old Adam Lanza, also killed his mother, Nancy, at home and committed suicide when police arrived at the school.

“One of the things that we really talked about quite a bit was that we need to understand the story of Adam Lanza and Nancy Lanza, and we don’t really have it,” Jackson said. “We got the littlest taste with the state’s attorney’s report. It was fleshed out a little bit here, but there’s still more, particularly for the folks who are treatment professionals. In order to understand how he got to where he was from a treatment standpoint, they’re going to need a little bit more.”

The Connecticut State Police released reams of documents Dec. 27 from the yearlong police investigation. It followed the earlier release of a summary report by State’s Attorney Stephen Sedensky III. Among the new documents were summaries of police interviews with mental health professionals who came in contact with Adam Lanza, but commission members said his actual records appear to be missing.

“It’s better than nothing to have these summaries, but these summaries are not by clinical people. They’re by the state police. And I don’t understand how it would not be better for us to have direct information that we can interpret for ourselves,” said Dr. Harold Schwartz, psychiatrist-in-chief at Hartford Hospital’s Institute for Living and a commission member who has suggested the panel directly approach Adam Lanza’s father and request that he provide such documents.

Jackson said a law firm is combing through the thousands of pages released by police and trying to index the information to make it easier for the commission to review it. In the meantime, he said, the panel is attempting to obtain primary documents. While he hasn’t yet asked the gunman’s father, Peter Lanza, for documents or to meet with commission members, Jackson said, “it is something that still may be helpful.”

“If there is a gap in the treatment record, understanding how that developed and what impact that later had on this enormous tragedy, that’s a systemic issue that needs to be addressed,” Jackson said.

It is good, Schwartz said, to finally have an official diagnosis of Adam Lanza on the record. Dr. Robert A. King, a professor at the Yale School of Medicine Child Study Center, told investigators that he diagnosed Lanza in 2006 with “profound Autism Spectrum Disorder, with rigidity, isolation and a lack of comprehension of ordinary social interaction and communications,” while also displaying symptoms of obsessive-compulsive disorder. But Schwartz said the synopsis provided of the Yale assessment “really doesn’t tell us a whole lot about the system.”

Lanza’s father has said his son had Asperger’s syndrome, a form of autism. It is not associated with violence.

Mental health professionals who sit on Malloy’s commission have said they ultimately want to recommend how Connecticut and other states can better help families like the Lanzas, who may be struggling to find appropriate mental health care for their children.

“Every incremental piece of information that we can have, I think, just adds to our growing body of knowledge, both about the mental health system and how to make it better for everybody and potentially about the minds of mass murderers and their developments,” Schwartz said.

A similar commission was created in the wake of the 2007 massacre at Virginia Tech. Schwartz said that panel was provided with the medical records of the shooter and information about how he had been committed on an outpatient basis for a psychiatric evaluation but didn’t follow up, ultimately slipping through the cracks.

“Because they knew, they had the information from his psychiatric history, they were able to focus on an important issue in public policy and make recommendations about it,” Schwartz said. Connecticut legislators have discussed the possibility of instituting outpatient commitment following the shooting at Sandy Hook but have not yet made any changes to current law.

Besides compiling the mental health recommendations, the commission still needs to review its earlier suggestions on gun laws and put together recommendations on school safety. Jackson said he hopes to have a final set of proposals ready by the end of March but acknowledged that is an ambitious deadline.